Metallic vapor rectifier



March 1, 1932. s. WIDMER METALLIC VAPOR RECTIFIER Filed Sept. 13, 1929 //v vs/v TOR flrromvir Patented Mar. 1, 1932 UNITED STATES PATENT- OFFICE j STEFAN WIDMER, OF BADEN,-SWITZERLAND, ASSIGNOR TO AKTIENGESELLSCHAIT BROWN BOVERI 8c CIR, F BAD'EN, SWITZERLAND, A JOINT-STOCK COMPANY OI" SWITZERLAND METALLIC vnron RECTIFIER Application filed September 13, 1929, Serial No. 392,423, and in Germany september 20, 1928.

This invention relates to improvements in electric current rectifying devices and, particularly, to rectifying structures of the metallic vapor type provided with means sformed and arranged to diminish the vapor density ahead of the anode.

In an electric current rectifying device of the metallic vapor type, the electric arc flowing therethrough mechanically carries large 10 quantities of the cathode material, which is usually mercury, from the cathode and from the condensed mercury flowing from the walls and over the bottom of the rectifying structure to the cathodewell, into the are guides surrounding the anodes. Such action increases the vapor density in the are guides and greatly increases the danger of formation of a cathode spot on the anode which would permit a flow of reverse currents or backfiring through the structure. Efforts have been made to decrease the vapor density adjacent the anodes by diminishing the crosssection area of the are guides at the opening thereinto and to obtain the same result by extending the arc guides into closely adjacent relation with the bottom of the rectifier tank which is generally cooled. The Vapor density within the are guides is actually increased by extending the arc guides adjacent the bottom of the rectifier because contact with the walls of the are guides by the arc largely nullifies the cooling effect of the bottom wall on the metallic vapor within the arc and the heating action of the are on the mercury flowing over the bottom of the rectifier tank causes revaporization of large quantities of the mercury. The present invention accordingly provides a structure by which the mass of metallic vapor within the are guides may be decreased and the danger of mechanically carrying portions of the cathode material into the arc guide by the arc may be entirely avoided.

. It is among the objects of the present invention to provide an electric current rectifying device in which the arc guides surrounding the anodes are formed and arranged to prevent the entrance of mechanically carried particles of the cathode material into such guides.

Another object of the present invention is to provide an arc guide structure and arrangement for electric current rectifying devices of the metallic vapor type in which the formation of the are guides and the arrangement thereof is such that the greatest possible spacing is obtained between the edge of'the cathode well and the edge of the arc guide fying device embodying the presentinven tion, and

Fig. 2 shows a horizontal cross-section, taken on the line A-A, of the embodiment shown in Fig. 1.

Referring more particularly to the drawings by characters of reference, the reference numerals 1 and 2, respectively, indicate the side walls and bottom of an electric current rectifying structure which are formed as double'walls to provide for a circulation of a.

coolin medium therethrough. The bottom- 2 of the rectifier is formed with an aperture located approximately centrally therein which aperture is closed by an annulus of insulating material 3 and a bottom plate 4 for the purpose of forming a container or well to receive the cathode material 6. The operating space of the rectifier structure is enclosedby a top portion 7 having an extension 8 in communication with the operating space for the purpose of receiving and condensing the mercury vapor arising from the cathode 6.

A pluralityof anodes 9 extend through the cover 7 ofthe rectifier in insulated relation therewith. The anodes 9 are surrounded by are guides 11, having a substantially 'cylindrical upper portion adjacent the anodes, which are guides extend into closely ad'acent relation to the bottom 2 of the recti er tank and terminate in a plane forming an angle with the bottom. The lower portions ofthearc guides are deformed from the cylindrical shape into the'shape of an ellipse and are arranged with the greatest radius of ing diminished cross section area at the open end thereof, namely the increasing of the resistance to the flow of the arc and the arc drop, is accordingly avoided and the arc drop instead of being increased is decreased. The edge of the are guides adjacent the edge of the cathode may also be extended toform a baflle about which the electric arc and the metallic vapor carried thereby must pass before entering into the arc guide or the plane of the open ends of the are guides may form an angle with the bottom as shown. Such structure of the arc guide would further decrease the amount of metallic vapor mechanically carried from the cathode by the electric arc.

Although but one embodiment of this invention has been illustrated and described, it will be understood that various other embodiments are possible, and that various other changes may be made without departing from the spirit of the invention or the scope of the claims.

The invention claimed is:

1. An electric current rectifying device comprising an operating chamber, a cathode within said. chamber, a plurality of anodes extending into said chamber, and are guides of substantially uniform cross section area and varying shape enclosing said anodes and gxtending toward the bottom of said cham- 2. An electric current rectifying device comprising, an operating chamber, a cathode within said chamber, a plurality of anodes extending into said chamber, and are guides enclosing said anodes and extending toward said cathode, said guides being circular in form adjacent said anodes and being deformed from the circular form at the end extending toward the bottom of said chamber.

3. An electric current rectifying device comprising an operating chamber, a. cathode within said chamber, a plurality of anodes extending into said chamber, and are guides enclosing said anodes and extending toward said cathode, said guides being circularly formed about said anodes and deformed coaxially with the circular portion thereof to form an ellipse at the end adjacent the bottom of said chamber.

4. An electric current rectifying device comprising an operating chamber, a cathode Within said chamber, a plurality of anodesextending into said chamber, and are guides enclosing said anodes and extendin toward said cathode, said guides being circularly formed about said anodes and deformed c0- axially with the circular portion thereof to form an ellipse at the end adjacent the bottom of said chamber, said guides beingarranged with the short axis of the elliptical portion thereof extending toward said cathode.

In testimony whereof I have hereunto subscribed my name this 27th day of August,

A. D. 1929. V

STEFAN WIDMER. 

